Staple driving machine



Oct. 19, 1954 Filed Sept. 8, 1950 s. LESTER 2,691,778

STAPLE DRIVING MACHINE;

4 Sheets-Sheet l INVENTOR. Ls/4 0A A 5 725 Oct. 19, 1954 s. LESTER I 2,691,778

STAPLE DRIVING MACHINE Filed Sept. 8, 1 950 4 Sheets-Sheet 2 WW .9404 4625721? A70 /20 Y 4 ff'ae/vzrzs.

Oct. 19, 1954 s. LESTER 2,691,778

STAPLE DRIVING MACHINE Filed Sept. 8, 1950 4 SheetsSheet 3 INVENTOR.

BY w cal Oct. 19, 1954 s. LESTER 2,691,778

STAPLE DRIVING MACHINE Filed Sept. 8, 1950 4 Sheets-Sheet 4 Patented Oct. 19, 1954 T .OFFICE STAPLE DRIVING MACHINE Saul Lester, New York, N. Y., assignor to Lou Obstfeld, Brooklyn, and Abraham Obstfeld,

New York, N. Y.

Application September 8, 1950, Serial No. 183,777

15 Claims.

This invention relates to staple driving machines, and more particularly to small desk-type staplers. The term stapler is employed for convenience, but the machine may also be used as a tacker.

The primary object of my invention is to generally improve staple driving machines. A more specific object is to provide such a machine in which the core may be released from the magazine and turned out to a position where it is fully exposed on all sides. Another object is to fully open the staple drive channel to clear the same of jams, and with this object in view the forward end of the staple core is employed as the inner side of the drive channel so that when the core is turned out the drive channel is opened up.

Another object is to provide appropriate means for retaining the stapes in the magazine when the core is swung out, thereby preventing ejection of staples by the pusher, and eliminating the need for a check dog or other form of safety tievice to prevent staple ejection. For this purpose a ledge is formed on each side wall of the magazine beneath the lower ends of the staple legs, and these ledges serve further as spacer means to center the core between the side walls of the magazine.

In accordance with further features and objects of the invention, the core is pivoted near its rear end and held by a releasable latch near its forward end. The said latch engages outwardly projecting tabs on the staple core by moving forward. The core is mounted to afford a slight longitudinal movement, and the resilient means operating on the latch is made powerful enough to serve also as means to resiliently close the staple drive channel. In many cases a potential staple jam may be cleared automatically by the ability of the inside wall of the staple drive channel (together with the entire staple core) to move rearwardly. Moreover, a single spring is preferably employed for three purposes, the said spring acting to raise the staple driving lever, to engage the latch, and to close the drive channel.

A still further object of the invention is to facilitate swinging the core out of the magazine after releasing the latch, and for this purpose a part of the base is preferably so arranged as to engage a part of the core when the base is swung around away from the magazine. The base may then be used as a lever for urging the core out of the magazine.

Still another object is to provide a front stop for the staple pusher to prevent possible injury by the staple driving blade when the last staple has been used. This stop bears against a part of the staple core, and is preferably cam-shaped in such a manner as to be made effective whenever the core is returned to the magazine. Ihc latch for holding the core in the magazine is also preferably cam-shaped so that all of the parts may be forced together by simply bearing downward on the cap of the machine.

A further object of the invention is to so design the machine, including the staple core, staple pusher, and the drive channel, as to effectively handle a slope leg staple. A still further object is to provide an improved means for anchoring the rear end of the staple pusher assembly in the machine. A further object is to provide a simplified and inexpensive stroke control mechanism. Still another object is to simplify and improve the assembly of the frame and magazine and other parts of the machine to provide a strong, rigid and sturdy assembly requiring the use of only a few rivets.

To accomplish the foregoing general objects, and other more specific objects which may hereinafter appear, my invention resides in the staple driving machine elements and their relation one to another as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings, in which:

Fig. 1 is a side elevation of a staple driving machine embodying features of my invention;

Fig. 2 shows the same with the base turned away from the stapling arm either for use as a tacker, or preparatory to turning the core out of the magazine;

Fig. 3 shows the core turned out of the magazine;

Fig. 4 is a fragmentary elevation similar to the center part of Fig. 2, but drawn to enlarged scale;

Fig. 5 is a fragmentary elevation similar to the center part of Fig. 3, but drawn to enlarged scale;

Fig. 6 is a section taken approximately in the plane of the line of Fig. 4;

Fig. '7 is an end view of the staple core, looking in the direction of the arrows 2-7 of Fig. 16;

Fig. 3 is a perspective view of the rear end of the base showing the bearing ears which receive the pivot pin for the stapling arm;

Fig. 9 is a longitudinal section taken in elevation through the machine;

Fig. 10 is a partially sectioned elevation show- 3 ing the staple core moved downward out of the magazine;

Fig. A is a fragmentary partially sectioned view generally like the upper part of Fig. 10, but showing the latch arms in retracted or rearward position, and with the staple pusher and guide rod and feed spring omitted.

Fig. 11 is a partially sectioned side elevation of the staple pusher assembly;

Fig. 12 is a plan view of the staple pusher;

Fig. 13 is a section through the staple pusher taken approximately in the plane of the line l3l3 of Fig. 12;

Fig. 14 is a section through the upper rear portion of the staple pusher rod, taken approximately in the plane of the line l4i4 of Fig. 11;

Fig. 15 is an exploded perspective view showing some of the main parts of the stapling arm;

Fig. 16 is a side elevation of the staple core;

Fig. 17 is a transverse section through the core, drawn to enlarged scale and taken approximately in the plane of the line l'l-Il of Fig. 16;

Fig. 18 is a side elevation of the forward portion of the stapling arm with the cap removed;

Fig. 19 is a section taken approximately in the plane of the line l9l8 of Fig. 18, with the staple driver in elevated position;

Fig. 20 is a similar view with the staple driver moved partway through its driving stroke;

Fig. 21 is a section taken approximately in the plane of the line 2I--2l of Fig. 18;

Fig. 22 is a section taken approximately in the plane of the line 22--22 of Fig. 9;

Fig. 23 is a side elevation similar to Fig. 1 but showing a slightly modified form of the invention;

Fig. 24 is a partially sectioned elevation generally similar to Fig. 9 but showing the modification;

Fig. 25 is a perspective view of a leaf spring forming a main part of a stroke control mechanism; and

Figs. 26-29 are sections taken approximately in the plane of the line 26-26 of Fig. 24 and showing progressive stages in the operation of the stroke control mechanism.

Referring to Fig. 1 of the drawing, the desk stapler there shown comprises a staple driving arm A pivoted on a base B and. having a cap C.

The arm and base are pivoted by a pin l2 carried by bearing ears M on the base. The base further carries an anvil it against which the staples are clenched, and a leaf spring 12 for elevating the stapling arm to the position shown. The cap 0 is pivoted at 34.

The base may be swung around the pivot it to a position approximately in alignment with the arm A, this relation being shown in Fig. 2. In such case the device may be used as a tacker for driving staples in depth as, for example, into a bulletin board.

The operation of the stapler may be described briefly with reference to Fig. 9. To load the machine the rear portion 22 of a staple pusher assembly is disengaged and pulled rearwardly (to the left), thus removing the pusher rod 26, the pusher spring 26, and the pusher 28. A stick of staples is slid into the rear of the machine over the exposed rear end of a staple core 32. The pusher is then re-inserted in the machine behind the staples and the part 22 engaged as shown. By depressing the cap 0 the staple driving lever 32 is moved downward about pivot pin 34. The lever carries with it the staple driving blade 35 which in turn drives the endmost staple through the staple drive chamiel 38, and through the material being stapled, whereupon the ends of the staple are clenched by anvil 4E1. When pressure on cap C is relieved the spring 18 raises the arm A, and the spring #2 raises the lever 32 and the cap C.

An important feature of the present invention is the fact that the core may be released and turned out of the magazine to fully expose the same. This is illustrated in Fig. 10, in which it will be seen that the staple core 30 has been turned downwardly out of the magazine 44. They are relatively movable about the pivot pin l2 previously referred to. The core is normally held in the magazine by latch mechanism, one arm of which is shown at 45 in Fig. 1, the said arm having a hook engaging a tab .8 bent outwardly from the side wall of the staple core. The parts 45 and 48 are also shown in'Figs. 9 and 10. Figs. 16 and 17 show how the tabs 58 are bent outwardly from the side walls 56 and 52 of the staple core 30.

The latch is best shown in Fig. 15, it comprising an inverted U-shaped piece of metal, the side legs 46 of which are joined by a bridge 56. The latch is dimensioned to fit around or to straddle the magazine 44. The forward edge of each arm 45 is notched or hooked as shown at 55, while the rear edge has small finger tabs bent outwardly as shown at '58. The side walls of the magazine M are cut away as indicated at 66 to receive the outwardly bent tabs at of the staple core.

Referring now to Fig. 10A and Fig. 18, the latch arms 46 are urged forward by suitable resilient means, here indicated by one end of the spring 42. The spring pressure may be exerted downwardly, because the latch has so substantial a width that any rearward or opening movement of the latch raises the rear edge of the top or bridge portion of the latch against the spring 42. This is shown by the change from Fig. 10 with hook arms 45 forward, to Fig. 10A with the hook arms rearward. The change is resisted by the downward pressure of spring 42. In Fig. 18 it will be evident that the core may be rotated out of the magazine by simply drawing the tabs 58 rearward with the fingers of one hand to release the latch, and at the same time pulling the tabs 48 downward with the fingers of the other hand to pull the core out of the magazine to a position such as that shown in Fig. 10. This exposes the entire magazine for examination, and for removal of any jammed staples.

What is perhaps more important, it opens up the staple drive channel. Referring to Fig. 9, the forward side of the staple drive channel is provided by a front wear plate 64. The rear side of the staple drive channel is the forward end of the staple core 30. Referring to Fig. 10, this includes the forward edges 56 of the side walls of the core and also a front wall 68 here shown as formed integrally with and bent upward from the bottom wall 10 of the core. The detailed construction is best shown in Fig. '7, the upper part of wall 68 being received between the side walls Ell and 52, and the lower part of wall 68 fitting outside the ends of the side walls, in recesses as shown in Fig. 16. It will be evident from inspection of Fig. 10 that when the core 31! is pulled down out of the magazine the staple drive channel is completely opened, and any jammed staples will fall out of position, or if not may be readily removed.

As so far described the staple core is rotated out of the magazine by manual manipulation of the core tabs 48 and the latch tabs '46. However, another feature of the present invention, illustrated in Figs. 2 through 8 of the drawing, facilitates turning the core out of the magazine, and the base B may be used as a handle for this purpose. The general idea, is shown by the change from Fig. 2 to Fig. 3 of the drawing, for if the latch 46 in Fig. 2 is freed, and the base B is t-umed further away from the arm, it functions to swing the core 36 out of the magazine 44. For this purpose a part 72 (Fig. 4) of the base is so shaped as to bear against a. part of the core. More specifically, the bearing ears I4 of the base are bent inward somewhat near the bottom, as is best shown at 12 in Fig. 8, to register with and bear against the rear end of the staple core, as shown in Figs. 2, 4 and 6 of the drawing. Inasmuch as the point of contact is well below the pivot pin I2, continued or clockwise movement of the base relative to the magazine, from the position shown in Figs. 2 and 4, will force the core out of the magazine as shown in Figs. 3 and 5.

The staple stick is retained safely in the magazine when the core is turned out of the magazine. This is done by the provision of ledges 86, 88 (Fig. 15) extendingv inwardly from the side Walls of the magazine A, beneath the lower ends of the staple legs (Fig. 22). The normal cross-sectional configuration of the magazine and core is best shown in Fig. 21, the magazine 44 being an inverted channel having side walls I4 and I6, and a top wall I8, and the staple core being another channel having side walls and 52 connected by a bottom wall 10. The particular machine here shown is intended to handle a so-called slope leg staple disclosed in U. S. patent to Lou Obstfeld No. 2,321,847 issued June 15, 1943, and it is for that reason that the side walls 5'2 and I6 include sloping portions 82 and 84.

Referring now to Fig. 22, the side wall 1'4 of the magazine is indented to form a ledge 86, and the side wall I6 of the magazine is indented to form a ledge 88. These ledges are located near the forward end of the magazine as is best shownin Fig. 15. They are preferably indented far enough to reach the side walls 56 and 52 of the staple core. They thus act as spacer means to center the core within the magazine. They also serve to hold the staple stick in the magazine when the core is swung out of the magazine. In Fig. 9 the machine is shown empty, and the staple pusher 28 is so far forward that the section of Fig. 22 passes through the pusher. Consequently in Fig. 22 it is the pusher 28 that is shown rather than staples. However, the cross-section of the pusher duplicates that of the staples, and therefore Fig. 22 may be viewed as though showing a staple instead of a staple pusher at 28. It will be understood that when the machine is empty or nearly empty the ledges 86 and 88 hold the pusher itself when the core is turned out of the magazine.

The staple core is preferably arranged to permit a slight longitudinal movement relative to the magazine. For this purpose the bearing holes $6 at the rear end of the core, best shown at the left of Fig. 16, are slotted or elongated instead of being made round holes. The staple core is normally urged forward until its front end bears against the parts 92 and 94 (Fig. 15) of the front wear plate 64, thus leaving the desired staple drive channel therebetween. For this the front wall 68 is given extra width as shown in Fig. 7.

The core is normally urged forwardly by the action of the latch 46 previously described, for it will be evident from inspection of Fig. 1, Fig. 9, or Fig. 18 of the drawing that the forward pressure of the latch hooks 46 against the tabs 48 of the core urges the core forwardly. In the event of a staple jam, however, the drive channel may be expanded by rearward movement of the core againstthe pressure of the latch. The latch then moves rearward, as shown in Fig. 10A, except that the movement needed would be less than shown in Fig. 10A. For this purpose it is necessary to not only elongate the holes 60 (Fig. 16) as previously mentioned, but also to make the notches 60 in the side walls of the magazine wider than the outwardly projecting tabs 48 of the staple core, so that the tabs will have room to move rearwardly when the drive channel expands to clear itself.

In the present construction three different spring functions are fulfilled by a single main spring. The spring is a heavy wirespring best shown at the top of Fig. 15. It comprises an upper arm I66 bent sidewardly at I62. The spring has a number of convolutions at I 64, and extends forward to form the bottom spring arm 42 previously mentioned. The coils I64 are received about a sleeve I66- surrounding the pivot 34 of the staple drive cap 0 (not shown in Fig. 15). Referring now to Fig. 9, it will be seen that the part I62 of the upper arm Hill of the spring underlies the staple drive lever 32 and urges it upwardly. This is the primary purpose of the spring, it being a restoring spring for raising the staple driver 36, the lever 32, and the cap C.

However, the pressure of the lower arm 42 on the wide top surface 54 of the latch causes the latch to assume the locking position shown. It will be observed that the side walls I 68 of the frame H6 have triangular notches H2 at the bottom. The top wall 54 of the latch passes through these notches IIZ, with th result that the latch pivots about its forward edge. Thus the spring 42 tends to turn the latch counterclockwise about its forward edge, and so to swing the hooks of the latch forward. This is shown by the change from Fig. 10A to Fig. 10. This causes the hooks to engage the tabs 48 of the staple core and to prevent downward movement of the staple core. The third function of the spring is to maintain the staple drive channel closed to its normal dimension, yet to permit yielding movement for relief of an oversized staple or staple jam by permitting rearward movement of the entire staple core when necessary. This is a change somewhat as from Fig. 10 to Fig. 10A, except that the magazine would be closed, as in Figs. 1, 9, and 18, and the needed movement would be less than that shown in Fig. 10A.

Referring to Fig. 15 it will be noted that the staple driving blade 36 is stopped inward or shouldered slightly at 37. These shoulders act as motion-limiting stops to limit the upward movement of the blade. This will be seen from inspection of Figs. 19 and 20, the upper or narrow part of the blade sliding between the hook portions I38 of the frame, and the lower or Wider portion of the blade sliding in the front plate 64. When the blade rises to the height shown in Fig. 19 the shoulders 31 bear against th hooks I36 and prevent further upward movement. This acts as a motion-limiting means to prevent the main sprin from raising the cap C and the drive lever 32 any higher than shown in the various figures of the drawing, and, of course, from pulling the blade upward out of the drive channel.

Referring now to Figs. 11 and 12, the staple pusher is an inverted trough-shaped piece of sheet metal, the top wall II4 of which has lugs H6 and H8 struck downwardly therefrom, and perforated to receive the pusher rod 24. In addition the top wall has a front stop I20 struck downwardly therefrom, as best shown in Figs. 11 and 13. The purpose of this stop will be evident from inspection of Fig. 9 in which it will be seen that even after the last staple has been driven the pusher 28 does not move forward beneath the staple driver 36. Instead the front stop 12c bears against the front wall 68 of the cor and limits the forward movement of the pusher to a point where the forward edge of the pusher just clears the staple driver.

The pusher is freely slidable on rod 2t, and is urged forward by spring 26, the forward end of which bears against lu lit, and the rear end of which bears against a lug 21 formed on rod 24 (Fig. 11).

In accordance with a further feature of the present invention thelower end of the front stop of the pusher isgiven a sloping cam shape clearly seen in Figs. 9, and 11. In Fig. 10 the staple core has been SWlll'lg out of the magazine and at such time the front wall 68 of the core is no longer engaged by the pusher stop I20, which then moves forward into the staple drive channel as shown in Fig. 10. This does not endanger the pusher because no one is likely to depress. the cap atthis time, and could not do so forcibly as h would have nothing to bear against. However, when the core is restored to the magazine the cam shape of the stop IZIJcauses it to move the pusher back to desired position, as shown in Fig. 9. Thus if someone bears down on the cap C and'so moves the magazine forcibly against the core, the pusher is not endangered becaus it is retracted by the cam action at the lower end of stop I20.

At this time it may be pointed out that the lower ends of the latch arms 46 are also given a curved or sloping cam shape. The core can be pushed upward into the magazine, or th magazine pushed downward around the core, and the latch will turn rearwardly on striking the outwardly projecting tabs 48 of the core until the tabs move above the hooks, whereupon the latch is swung forward by its spring to lock the core in position. Thus after the machine has been opened up as shown in Fig. 10, it may be closed to re-assemble the same by simply bearing down on the cap from above.

Referring now to Fig. 15, the front wear plate 64 is made of heavy gauge metal, and the desired staple drive channel is provided by striking a portion of this metal forwardly. The part that is thus struck forwardly is given a special shape shown in Fig. 15, but the action of which may be better explained by reference to Figs. 19 and 20. In those figures it will be seen that the staple I22 is received in a recess shaped to fit the same. The drive plunger 36 slides between parallel walls, one of which diverges as shown at I24 to conform to the sloping leg I26 of the staple. The lower part of the wall I24 is then curved inward as indicated at I28 to cam the sloping leg inward to the parallel relation shown in Fig. as the staple driver 36 forces the staple I22 downward. If the staple is used as a tack the legs pass straight into the material receiving the same, while if the staple is being clenched the legs are bent by a clenching anvil schematically indicated in broken lines at the bottom of Fig. 20.

The stapling machine is assembled as follows: Referring to Fig. 15, the top wall I8 of the magazine has a pair of tongues I30 struck upward therefrom. The bottom wall I32 of the frame no is slotted or cut away to receive the tongues I36, this being indicated at- I34, I36. Thus the frame IID may be placed over the magazine I8 and pulled forward, with the tongues 13%! acting as hooks receiving the frame, the latch 46 being first placed over the magazine and thus located between the frame and the magazine and resting in the notches II2, H2. The forward edges of the frame are shaped to provide hooks I38 dimensioned to receive the upper edge of the front wear plate I34. The latter is recessed as shown at lit to receive the hooks I38 and to hold the latter against spreading. At the same time the front wear plate holds the frame against rearward movement. The lower edge of the front wear plate is secured in position by means of a pair of rivets passing through holes I42 and through mating holes Hi l in cars Hi6 bent outwardly at the forward end of the magazine. Thus two rivets serve to hold the front plate, the frame, and the magazine in assembled relation. If desired, and preferably, the top wall of the magazine is struck upwardly into the bottom wall of the frame after the parts have been assembled, thus forming a locating dot indicated at M8 in Fig. 9.

The base B has a generally flat surface I50 (Fig. 9) with a flange I52 formed around the side and forward edges. The anvil 4! may be provided with a pair of locating dots which are received in mating holes in the base (not shown) following which the anvil is secured against the base by spot welding .at a single point.

Referring to Fig. 8, the bearing ears M are formed integrally with a bottom plate I54 which in turn is secured to the top of the base. For this purpose it may be located by means of a locating dot received in a hole indicated at I56 (Fig. 9) and is secured in position by means of a single rivet I58 which serves also to hold the rear end of leaf spring IS. The leaf spring is held against sideward or turning movement about the rivet I58 by the bearing walls I4 between which the spring is received.

To assemble the magazine to the base the piv- 0t pin I2 is passed through the magazine, and bearings I4, and the rear end of the staple core 36. The pivot I2 may have a solid head at one end, and be riveted or eyeleted at the other end.

Reverting now to Figs. 9 and 15, the staple driving blade 36 is slid upward into position, and the staple driving lever 32 is placed in the frame IIl together with the spring IIIB, the parts being held in position by the bearing sleeve I05. This is passed through holes Iliil in the frame, and the sleeve may be recessed slightly at I62 to locate the same against axial movement in the frame. At this time the forward end of the lever 32 has, of course, been inserted in the mating slot I64 of the blade 36. The front plate 64 is slotted at 65 to receive the end of lever 32 when in lowest position. The cap C is added by simply placing it over the staple driving lever, with the forward end of the lever received in a mating slot in the forward end of the cap, this slot being shown at I 66 in Fig. 9. The cap is held in position by means of a relatively slender pivot pin shown at 34 in Fig. 15, the said pin passing through the sleeve I86 and through the side walls of the cap, one end of the pin being headed, and the other end being expanded or eyeleted to hold the same in place.

To complete and load the machine it is merely necessary to slide a clip of staples through the rear end of the machine over the core, and to then add the staple pusher assembly, the pusher being slid over the core, and the rod being pressed inwardlyuntil the end 22 is hooked in position. For this purpose the downwardly turned end 22 is flattened, as indicated at I68 in Fig. 14, and the side edges are notched at Illi. The top Wall of the staple magazine is provided with a generally triangular hole I12 shown in Fig. 9 and more clearly in Fig. 15. It will be evident that the pusher spring urges the end 22 rearward and thus causes the notches I'Ill to become anchored between the converging side walls of the triangular hole I12.

A modified and slightly more refined form of the invention is illustrated in Figs. 23 through 29 of the drawing. The machines are essentially the same, except for three differences hereinafter described. One concerns the staple pusher assembly and the method of securing the rear end of the pusher rod. The reversely turned hook previously shown is eliminated, and instead the rear end of the pusher rod I39 is riveted at I82 (Fig. 24) to an arm I8 turned downwardly from the top wall N36 to a sheet metal cover. This cover has side walls I88 best shown in Fig. 23, the lower part of said side walls preferably being slightly roughened or knurled. The lower end of the arm I84 is bent to somewhat hook shape, as indicated at ISO in Fig. 24, and is so arranged that it may be hooked within the pivot pin I2 previously referred to. The triangular notch shown at H2 in Fig. 15 may be omitted. To place the pusher assembly in position the pusher is slid on the staple core until the cover I86 is forward far enough for the hook I90 to be lowered into position within the pivot l2.

A second difierence in the present machine lies in the addition of stroke control mechanism. A stroke control mechanism prevents the staple driving blade from rising once it has started downward, unless and until the stroke has been completed, and thus helps avoid the jamming of one staple on top of another. Stroke control mechanisms are already known, and are often employed, but the use of such a mechanism is less important in the present machine than in most, and is not employed in the machine described in connection with Figs. 1-22. The reason it is less important is because of the ability of the staple drive channel to expand and so to clear jams of itself, and also because of the possibility of swinging the core out of the magazine and thus fully opening the staple drive channel in the event of a jam which does not clear itself. However, when slight additional cost is permissible the present machine may be provided with stroke control side walls of the frame, through hole 2| (Fig. 15),

as shown at 200 in Fig. 24.

To cooperate with the spring the staple driver 282 has a lug 2M struck rearwardly therefrom, the said lug then being disposed over the detent I94 previously referred to.

The action of the stroke control mechanism may be explained with reference to Figs. 26-29 of the drawing. In rest position the lug 2% of staple driver blade 222 is disposed above th detent ltd and the cam I96, as shown in Fig. 26. As soon as the driver starts downward it deflects and moves past the ole-tent IE4 which then springs inward over the lug 282 as shown in Fig. 27. It thus becomes impossible for the driver 202 to rise to initial position, and this prevents the feed of another staple, for the lower end 266 of the driver blade remains across the end of the staple stick and prevents the feed of any further staples.

In Fig. 28 the staple driving stroke is nearly completed, and it will be seen that the lug 2M bears against the cam flit and straightens it to vertical position from its initial biased position. On slight additional movement to complete the driving stroke the lug 2% moves beneath the lower end of the cam Ids, which then springs inward so that the lug is beneath the outside of the cam instead of on the inside of the cam. The staple driver is then permitted to rise under the influence of the main restoring spring, as shown in Fig. 29, and the lug 2M moves outside the leaf spring I92. It is thus able to move to fully elevated position, the detent I24 being ineffective because it is on the inside of the spring. Thus in normal operation the driver may be worked repeatedly, the lug 2% moving downward on one side of the leaf spring, and upward on the other side or the leaf spring.

The integral nature of the lug 204 will be seen in Fig. .5, it being bent rearwardly by incising one side edge of the blade. The lug 224 is, of course, unnecessary in the first form of the machine, but is shown in Fig. 15, and in practice may be provided so that all of the blades may be made alike from the same die. It is for the same reason that the hole 2H1 is shown in the side of the frame in Fig. 15, this hole not being used in the first form of the invention, but being employed for the rivet 2053 (Fig. 24) which holds the stroke control spring in position when stroke control mechanism is employed. Similarly the notch 225 is provided to clear the lug 2M when assembling the machine.

The third difference in the modified machine is the addition of a molded rubber base 2I2, best shown in Figs. 23 and 24. This base is molded with a large recess 2 I 4 in its top surface to receive the metal base B previously described. It further includes an inwardly disposed flange 2I6 which overlies the metal base to hold it securely within the rubber base. The rear end of the rubber base may be tapered off or streamlined, as shown at 218. The addition of the rubber base thus enhances and enriches the appearance ofthe machine, as well as acting as a cushioning and noise-reducing device.

Thus for minimum cost the machine may be made as shown in Figs. 1-22, but at slightly greater price the machine may be made in more elegant form by the addition of the stroke control mechanism, the staple pusher cover at the rear end of the machine, and the relatively large ornamental rubber base.

Figs. 26, 27 and 28 may also be referred to for an understanding of the action of the machine in driving a slope leg staple. The staple I 22 is shown in Fig. 6 in its initial or slope leg condition. As it is driven downward the sloping leg [23 is forced inward to a perpendicular position by the camming portion 125 of the drive channel, as shown in Fig. 27. During the remainder of the driving action the legs remain perpendicular, as shown in Fig. 28.

In Figs. 9, and 24 of the drawing the top or bridge 54 of the latch is shown pressed down flat on the magazine, but it will be understood that this is primarily to simplify the drawing. In practice there is at least a slight clearance at the rear edge, or, in other words, the arms of the latch are disposed at a slight angle rearwardly, thus enabling the lower arm 42 of the spring to exert its downward pressure, which in turn causes forward pressure by the hooks of the latch and thus resiliently closes the staple channel.

It is believed that the construction, the method of assembly, and the operation of my improved staple driving machine, as well as the advantages thereof, will be apparent from the foregoing detailed description. It will be understood that features such as the swinging out of the core to expose the same and to open up the staple drive channel, or the floating mounting of the core to provide a resiliently closed staple channel are applicable to so-called tackers having no base or clenching anvil, as well as to machines having a base and anvil, and machines like that here shown which may be used either way. It will therefore be apparent that while I have shown and described the invention in two preferred forms, changes may be made in the structures shown, without departing from the scope of the invention as sought to be defined in the following claims.

I claim:

1. A staple driving machine comprising a stapling arm including a magazine, and a core housed therein, said magazine having top and side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, whereby the core may be swung out of the magazine to fully expose the same and at the same time to open the drive channel, the side walls of said magazine having ledges near the forward end at a point beneath the lower ends of the staple legs in order to hold the staples against moving down with the core when the core is swung away from the magazine.

2. A staple driving machine comprising a stapling arm including a magazine, a core housed therein, staple driving mechanism including a staple drive channel one side of which is formed by the forward end of the core, said magazine having top and side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, and releasable means for holding the core in the magazine, whereby the core may be swung out of the magazine to fully expose the same and at the same time to open the drive channel, the 'side walls of said magazine being indented near the forward end at a point beneath the lower ends of the staple legs in order to act as spacer means and in order to hold the staples against moving down with the core when the core is swung away from the magazine.

3. A staple driving machine comprising a stapling arm including a magazine, and a core housed therein, said magazine having top and side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, and releasable latch means for holding the core in the magazine, whereby the core may be swung out of the magazine to fully expose the same, said latch being an inverted U-shaped member disposed around the outside of the magazine and having hooks formed at the lower ends, said core having finger tabs struck outwardly to engage the hooks, and resilient means to yieldably hold the latch in looking position engaging the tabs of the core.

4. A staple driving machine comprising a stapling arm including a magazine, a core housed therein, staple driving mechanism including a staple drive channel one side of which is formed by the forward end of the core, said magazine consisting of top and side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, and releasable latch means near the forward end for holding the core in the magazine, whereby the core may be swung out of the magazine to expose the same and at the same time to open the drive channel, said latch being an inverted U -shaped member of substantial width disposed around the outside of the magazine and having finger tabs and hooks formed at the lower ends, said core having finger tabs struck outwardly to engage the hooks, means affording pivoting of the latch about its forward top edge, and resilient means bearing downward against the top of the latch to yieldab-ly hold the same in locking position engaging the tabs of the core.

5. A staple driving machine comprising a stapling arm including a magazine, a core housed therein, and staple driving mechanism including a normally open staple drive channel one side of which is formed by the forward end of the core, said core being movably mounted to afford longitudinal movement relative to the magazine, stop means to limit the forward movement of the core to an amount which keeps the staple drive channel open, and resilient means normally urging the core forward, whereby the machine is provided with a resiliently yieldable staple drive channel capable of yielding in the event of a staple jam in the staple drive channel.

6. A staple driving machine comprising a stapling arm including a magazine, a core housed therein, and staple driving mechanism including a staple drive channel one side of which is formed by the forward end of the core, said magazine consisting of topand side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, whereby the core may be swung out of magazine to fully expose the same and at the same time to open the drive channel, the rear end of said core having elongated bearing holes to afford a longitudinal floating movement of the core, and resilient means urging the core forward, whereby the machine is provided with a resiliently yieldable staple drive channel.

'7. A staple driving machine comprising a stapling arm including a magazine, a core housed therein, and staple driving mechanism including a driver lever, driver blade, and a drive channel one side of which is formed by the forward end of the core, said core being so mounted as to afford a longitudinal movement relative to the magazine, and resilient means having one end normally urging the core forward whereby the machine is provided with a resiliently yieldable staple drive channel, said resilient means having its other end reacting on and bearing upwardly on the driver lever and thereby serving to restore the lever to initial position.

8. A staple driving machine comprising a stapling arm including a magazine, a core housed therein, and staple driving mechanism including a driver lever, driver blade, and a drive channel one side of which is formed by the forward end of the core, said magazine consisting of top and side walls and being open'at the bottom, said core being pivoted to said magazine at the rear end, whereby the core maybe sprung out of the magazine to fully expose the same and at the same time to open the drive channel, the rear end of said core having elongated bearing holes to aiford a longitudinal floating movement of the core, and a single compression spring having one end bearing upwardly on the driver lever to raise the lever and the other end bearing downwardly on an angle lever serving to urge the core forward and so to resiliently close the staple drive channel.

9. A staple driving machine comprising a stapling arm including a magazine, a core housed therein, and staple driving mechanism including a driver lever, driver blade, and a drive channel one side of which is formed by the forward end of the core, said magazine consisting of top and side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, and releasable latch means near the forward end for holding the core in the magazine, whereby the core may be swung out of the magazine to fully expose the same and at the same time to open the drive channel, said latch being an inverted U-shaped member of substantial width disposed around the outside of the magazine and having hooks formed at the lower ends, means afiording pivoting of the latch about its forward top edge, said core having finger tabs struck outwardly to engage the hooks, and a single spring having one end bearing upward on the driver lever and the other end bearing downward on the latch whereby said spring serves to raise the lever and to engage the latch.

10. A staple driving machine comprising a stapling arm including a magazine, a core housed therein, and staple driving mechanism including a staple drive channel one side of which is formed by the forward end of the core, said magazine consisting of top and side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, and releasable latch means near the forward end for holding the core in the magazine, whereby the core may be swung out of the magazine to fully expose the same and at the same time to open the drive channel, said latch being an inverted U-shaped member disposed around the outside of the magazine and having hooks formed at the lower ends, said core having finger tabs struck outwardly to engage the hooks, the pivot of said core including elongated bearing holes to afford a longitudinal floating movement of the core, and a spring bearing on the latch to move it forward, whereby said spring serves to engage the latch, and to resiliently define the staple drive channel.

11. A staple driving machine comprising a stapling arm including a magazine, a core housed 'therein, and staple driving mechanism including a driver lever, driver blade, and a drive channel one side of which is formed by the forward end of the core, said magazine consisting of top and side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, and releasable latch means near the forward end for holding the core in the magazine, whereby the core may be swung out of the magazine to fully expose the same and at the same time to open the drive channel, said latch being an inverted U-shaped member or substantial width disposed around the outside of the magazine and having hooks formed at, the lower ends, said hooks being open in forward direction, means affording pivoting of the latch about its top forward edge, said core having finger tabs struck outwardly to be engaged by the forward sides of the hooks, the pivot of said core having elongated bearing holes to afford a longitudinal floate ing movement of the core, and a single spring having one end bearing upward on the driver lever and the other end bearing downward on the latch, whereby said spring serves to raise the lever, to engage the latch, and to resiliently close the staple drive channel to its minimum dimension.

12. A staple driving machine comprising a base, and a stapling arm pivoted thereon, said stapling arm including a magazine, a core housed therein, and staple driving mechanism, said magazine consisting of top and side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, and releasable means for holding the core in the magazine, whereby the core may be swung out of the magazine to fully expose the same and at the same time to open the drive channel, a part of said base having means to bear against a part of the core without bearing against the magazine when the base is swung completely around, whereby the base then acts as a handle to facilitate swinging the core out of the magazine.

13. A staple driving machine comprising a base having upstanding bearing ears near its rear end, and a stapling arm pivoted thereon, said stapling arm including a magazine, a core housed therein, and staple driving mechanism including a staple drive channel one side of which is formed 1 by the forward end of the core, said magazine consisting of top and side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, and releasable latch means near the forward end for holding the core in the magazine, whereby the core may be swung out of the magazine to fully expose the same and at the same time to open the drive channel, the bearing ears of said base being bent to engage the rear end of the core at a point oifset from the pivot, whereby the base may be used as a handle for facilitating swinging the core out of the magazine. I

14. A staple driving machine comprising a stapling arm including a magazine, a core housed therein and having a front wall, said magazine consisting of top and side walls and being open at the bottom, said core being pivoted to said magazine at the rear end, whereby the core may be swung out of the magazine to fully expose the same, a staple pusher slidable on said core, resilient means urging the pusher forwardly, and a front stop on the pusher, said front stop bearing against the inside of the front wall of the core and serving normally to prevent the forward end of the pusher moving beneath the staple driver blade, and the lower end of the front stop having a rearwardly sloping cam shape such that the pusher is forced back by the front wall hearing against the front stop and the front stop is thereby made effective whenever the core is swung back into the magazine about the pivot at the rear end.

15. A stapling machine assembly comprising a channel-shaped magazine open at the bottom, a channel-shaped frame open at the top, and a generally fiat. front plate, upwardly offset tongues at. the: top of the magazine, slots at the bottom of the frame to receive said tolzigues,v whereby the frame may be secured tothe magazine by moving the same forwardly beneath the tongues, the forward end of the frame being slotted to form downwardly facing hooks which receive the upper end of the aforesaid front plate, and the lower end of said front plate being secured to the forward. em'l of the magazine, whereby the latter rivets. hold all of. the parts in. assembled relation.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date White July 2, I889 Vogel Mar. I6, 1937 Germain Oct. 22, 1940 Vancura June 24, I941 Crosby Dec. 30, I941 Pankonin Feb. 16, 1943 Lindstrom Aug. 1, 1944 Maynard. Mar. 20, I948 Wampler Mar. 13, 1951' 

